The present invention relates to electrically operated valves of the type having a rotatable valve member received in the valving chamber in a valve body for, upon rotation, controlling flow between an inlet and outlet passage communicating with the valving chamber. Electric servo operated valves have found particular application in controlling flow of hot water to heat exchangers such as the heater core for heating the passenger compartment of a motor vehicle.
Currently it is necessary to offer an electrically controlled climate control system for the motor vehicle passenger compartment to be competitive in the automotive marketplace. This type of system has necessitated servo operation of the heater core water valve; and, in order to minimize the manufacturing costs of the motor and valve assembly, and to improve reliability and reduce the risk of leakage of the hot water circulated to the heater core, it has been desired to provide a permanently sealed assembly.
Heretofore, servo operated water valves for controlling flow of hot water to a motor vehicle passenger compartment heater core required a separate seal between the motor drive unit and the valve body and the use of separate fasteners to attach the motor drive unit to the valve body. This arrangement required separate assembly fixtures and additional operations in installing the fasteners, all of which resulted in relatively high manufacturing costs. Such fasteners, typically formed of metallic material, have been a source of metal corrosion and swelling which has resulted in rupture of the valve body and motor housing which are typically formed of plastic material. It has thus long been desired to find a way or means of assembling a servo operated rotary water valve for controlling flow in response to an electrical control signal and which does not require fasteners during assembly and is robust and relatively low in manufacturing costs enabling the valve to be competitive in high volume mass production.